This Stevia doesn't seem to have a bitter aftertaste, at least in the quantities that I use. While the vanilla scent in the bottle is strong, I don't find that it contributes any flavor to my food because I use so little stevia.

I never notice much of a flavour from these flavoured stevia drops (not just this brand, but others I have tried as well). It's probably because I don't use that much, so perhaps if you use a lot you will get a stronger vanilla flavour. Otherwise, this is a great, high quality stevia with no bitter aftertaste.